Question

HEEELP ME !!!!!!!
Determine the equation of each graph in the form y = acos(bx).
https://www.virtualhighschool.com/content/OSSD-v2/Department/Math/courses/MCR3U/ver-D/Transforming_Trig/images/45.png?_&d2lSessionVal=zz5owIE4LYpM64Qh3q7GmzDHv



and


https://www.virtualhighschool.com/content/OSSD-v2/Department/Math/courses/MCR3U/ver-D/Transforming_Trig/images/46.png?_&d2lSessionVal=zz5owIE4LYpM64Qh3q7GmzDHv


B) Determine the equation of each graph above in the form y = a sin(bx)

Answer 1

PLEASE HELP!!

Answer 2

in the first one it should be more or less clear that \(a=4\) because that is the highest point on the graph

Answer 3

what is the equation then?

Answer 4

\(b\) is found by setting \[\frac{360}{b}=1440\] and solving for \(b\) since the period of that function is \(1440\)

Answer 5

i.e. \(b=\frac{360}{1440}=\frac{1}{4}\)

Answer 6

wont b = 4?

Answer 7

@tkhunny can you help me?

Answer 8

b=4??

Answer 9

no it will not be 4, it will be \(\frac{1}{4}\) for sure

Answer 10

ok

Answer 11

so the equation will be y= 4cos(1/4x) ?

Answer 12

\[\frac{360}{b}=1440\iff 1440x=360\iff x=\frac{360}{1440}=\frac{1}{4}\]

Answer 13

yes or
\[4\cos(\frac{x}{4})\]

Answer 14

can you do the second one??

Answer 15

probably
let me look

Answer 16

this one looks like sine, but instead of starting at zero and going up, it starts at zero and goes down
so \(a\) will be negative

Answer 17

i can't really see how far down it goes
what is the lowest point on the graph?

Answer 18

-3

Answer 19

ok so \(a=-3\)

Answer 20

you do not see a full period here but you can figure it out from the picture, because half of the period is 90 degrees
therefore the full period is 180 degrees

Answer 21

ok

Answer 22

to find \(b\) as before, solve
\[\frac{360}{b}=180\] for \(b\)

Answer 23

the equation is -3cos(2x) ???

Answer 24

not cosine, sine

Answer 25

if it is right ...... can you do part b?

Answer 26

ok

Answer 27

i thought that was B

Answer 28

no you have to write the cos equation for the two graphs and then part b is writing the sine for the same two graphs

Answer 29

@tkhunny help!!